What is 1.4028 Stainless Steel?

1.4028 stainless steel, commonly known as 420J2 or UNS S42000 (higher carbon variant), is a martensitic stainless steel with increased carbon content within the 420 family. With carbon ranging from 0.26-0.35%, it offers higher attainable hardness and wear resistance than standard 420 (1.4021), making it particularly suitable for applications requiring superior edge retention and abrasion resistance, such as high-end cutlery, surgical instruments, and industrial blades.

 

This higher-carbon martensitic grade is standardized under key international systems.

Standard	Equivalent Grade
EN (Europe)	1.4028
ASTM/AISI (USA)	420J2, UNS S42000
JIS (Japan)	SUS420J2
KS (Korea)	STS420J2

Its elevated carbon content provides enhanced hardenability and maximum hardness compared to lower-carbon 420 variants.

Element	C	Si	Mn	P	S	Cr
Content (%)	0.26 - 0.35	≤ 1.0	≤ 1.0	≤ 0.04	≤ 0.03	12.0 - 14.0

Mechanical properties reflect the higher carbon content, with increased strength and hardness potential.

Condition	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HRC)
Annealed	~ 380 MPa	~ 700 MPa	~ 18%	~ 22 HRC
Hardened & Tempered	≥ 600 MPa	≥ 800 MPa	≥ 10%	53 - 58 HRC

 

Key Characteristics and Applications of 1.4028 / 420J2

Superior Hardness and Wear Resistance: Achieves higher maximum hardness (up to 58 HRC) than standard 420 due to increased carbon content, providing excellent edge retention and abrasion resistance.

Moderate Corrosion Resistance: Similar to standard 420, offers good resistance to mild environments, fresh water, and food acids, but is not suitable for severe corrosive conditions.

Magnetic and Heat Treatable: Strongly magnetic and responds well to heat treatment, though higher carbon requires careful control to avoid cracking.

Good Polishing Characteristics: Can be polished to a high finish, important for surgical instruments and quality cutlery.

 

Primary Applications:

High-End Cutlery: Professional kitchen knives, hunting knives, and pocket knives requiring excellent edge retention.

Surgical Instruments: Scalpels, forceps, retractors, and other instruments requiring sharp edges and sterilization resistance.

Industrial Blades: Slitting knives, shearing blades, and cutting tools for paper, plastic, and light metals.

Scissors and Shears: Professional shears, hair cutting scissors, and textile cutting tools.

Valve Components: Seats and stems in applications requiring wear resistance.

 

What is the difference between 1.4021 (420) and 1.4028 (420J2)?
The main difference is carbon content. 1.4021 has carbon 0.16-0.25%, while 1.4028 has carbon 0.26-0.35%. This higher carbon allows 1.4028 to achieve greater maximum hardness (58 HRC vs 55 HRC) and superior wear resistance, but at the cost of reduced toughness and slightly more difficult heat treatment. 1.4028 also has a slightly higher as-annealed strength but lower ductility. 1.4021 is preferred for applications requiring a balance of hardness and toughness, while 1.4028 is chosen where maximum hardness and wear resistance are critical.

 

How should 1.4028 stainless steel be heat treated?
Heat treatment requires careful control due to the higher carbon content. Hardening: Austenitize at 980-1030°C, with preheating recommended at 760-815°C to prevent thermal shock. Quench in oil or air depending on section size; oil quenching is typical for maximum hardness. Tempering: Temper immediately after quenching to relieve stresses, typically at 150-250°C for maximum hardness (53-58 HRC). Tempering at 350-550°C should be avoided due to embrittlement. For improved toughness with some hardness reduction, temper at 550-650°C, though this will significantly lower hardness to 35-45 HRC. Double tempering is often beneficial for stress relief and dimensional stability.

 

Looking for a Reliable Supplier of 1.4028 / 420J2 Stainless Steel?
GNEE Steel supplies high-quality 420J2 (1.4028) martensitic stainless steel in bar, wire, sheet, and strip forms, available in annealed condition for machining or pre-hardened to customer specifications. We provide full material certification (EN 10204 3.1) and processing support including precision cutting, grinding, and heat treatment services. If you have any requirements, please feel free to contact us.